Shell dredger



April 1961 E. L. PAULSON 2,978,819

SHELL DREDGER Filed Aug. 1, 1957 4 Sheets-Sheet 1 INVENTOR. 1 I Everett L. Puulscn T BY I :III WMJW/w/ Attorneys April 11, 1961 E. L. PAULSON SHELL DREDGER Filed Aug. 1, 1957- 4 Sheets-Sheet 2 I f I i i l l l l INVENTOR.

Everett L. Paulson Attorneys E. L. PAULSON April 11, 1961 SHELL DREDGER Filed Aug- 1957 4 Sheets-Sheet 5 Hill C INVENTOR.

Everett L. Paulso Way/W Attorn y April 11, 1961 E. PAULSON 2,978,819

SHELL DREDGER Filed Aug. 1, 1957 4 Sheets-Sheet 4 Attorneyq SHELL DREDGER Filed Aug. 1, 1957, Ser. No. 675,589

1 Claim. (Cl. 37--57) This invention relates to a dredger for retrieving material capable of being temporarily suspended in water such as pulverulent shells, silica silt and the like from the floor of a water body.

It is customary in dredging barges to employ some means for digging into the door of the bay or other water body to loosen the material forming the floor and then to provide a hoisting means for lifting the material onto the barge. After the material is deposited in the barge the materials are classified to either remove the water or to segregate the material by size or weight.

The principal object of this invention is to provide an improved dredging barge employing a propeller arranged to produce a high velocity water flow stream arranged to force. lighter materials comprising the water body floor into suspension and thereafter carry the water and suspended particles into a hopper within the barge for classification.

A feature and advantage of this device is that the propeller while creating the water flow stream provides propulsion for the barge.

Another object of this invention is to provide a foraminous transport tube through which water and suspended materials are disposed to travel into the body of the barge. The foraminous transport tube forms a classification means by which some water and smaller particles are classified from the tube during transportation of the water and suspended materials through the tube, thus providing a discharge from the discharge end of the tube comprising a substantially greater percentage of useable shells and the like than was heretofore possible with the employment of conventional transport tubes.

Another feature and advantage of this invention is to provide a shell and silica retrieving dredge or barge employing novel meansfor removing the shells from the bottom of the water body floor and thereafter transporting the shells and silica to the body of the barge without the need of any mechanical contact between the barge and the water body floor. By virtue of the aforesaid feature and advantage there is no impedance against forward movement of the barge so that the barge can be propelled with a greater economy and efiiciency then was heretofore possible with conventional barges having contact with the water body floor.

. Another feature and advantage of this invention is that the power generated to cause suspension of the retrievable material on the water body floor also creates a forward pressure tending to move the barge forwardly and also allowing the barge to be traversed in an are around a fixed anchor point solely by the power generated to effect the shell retrieving operation.

A further feature and advantage of this invention is that the direction of traversing of the barge in an are around a fixed anchor point can be varied so that the barge either travels in a clockwise or counterclockwise direction with respect to the fixed anchor point dependttes Patent ing solely upon the anchored position of the line conmeeting the barge of the fixed anchor point.

Another object of this invention is to provide means within the dredger barge for obtaining substantial classification of water from the retrieved shell material so that substantially dry material may be delivered to an adjacent carrier barge thus eliminating the need for the carrier barge to effect a substantial portion of the classification of water and silt from the shell and silica materials.

A still further object of this invention is to provide means for adjusting relative height of the propeller and transport tube in respect to the position of the Water body floor throughout wide variations of water depth.

A still further object of this invention is to provide means whereby the propeller and transport tube may be raised above the water line of the hull of the barge so that no part of these elements projects below the bottom of the barge to increase draft.

A still further feature and advantage of the mechanism in the aforesaid paragraph is that the propeller and tube elements may be raised above the water line of the barge so that they may be repaired or maintained without the necessity of dry-docking the barge or working on the components below the water line.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each of the several views.

In the drawings: 1

Fig. 1 is a cross-sectional elevated view of the dredger barge of this invention.

Fig. 2 is a top plan view of the dredger barge shown in combination with a load carrier barge.

Fig. 3 is a schematic view showing the arcuate traversing course of the dredger barge with respect to a fixed anchor point operated in accordance with the teachings of this invention.

Fig. 4 is an enlarged perspective of the shell and suspended material transport tube and hopper into which material is fed from the discharge end of the transport tube.

Fig. 5 is a sectional view of Fig. 1 taken at line 55.

Fig. 6 is a top plan of a modification of the invention in which there is provided means to vary the relative angle of the propeller.

Fig. 7 is a side elevation of Fig. 6 taken at line 66.

Fig. 8 shows a modification of the mouth portion of the transport tube wherein the mouth is flared to provide a larger intake area and the end of the tube is supported by rollers.

Fig. 9 is an end view of Fig. 8.

Fig. 10 is an end view of another modification of the transport tube wherein the transport tube is supported by runners.

Referring'now to the drawings and with particular reference to Figs. 1, 2, 4 and 5 the dredger barge of this invention comprises a hull generally indicated at A having a stern 13 and a bow 14. The hull is formed with two axially aligned centrally disposed well-s 15 and 16. Well 15 is arranged to receive a water stream generating apparatus generally indicated at B. The water stream generating apparatus comprises a propeller 18, a propeller shaft housing 19 in which the propeller shaft is housed and a power. source such as motor 20 arranged to power propeller 18 through a transmission 22. Transmission 22 is arranged to allow pivotal movement of the housing 19 with respect to barge hull A. so that the propeller and housing may be relatively raised or lowered.

A pulley mechanism 25 is provided suspended from a davit 27 to provide means by which the propeller may be raised or lowered. Well 15 is formed of sufiicient length so that the entire propeller and housing 19 may be raised to a position fully. above the water line of hull A, By thismeans propeller 18. may berepaired or re placed without the necessity of dry-docking the barge or working below the water line. It is also evident that by this means the barge can be hauled in areas of extremely shallow depth wherein the propeller is arranged either coincident with or above the bottom of the barge so that the minimum draft of hull-Acan be. taken advantage of.

Pulley mechanism 25 also allows for the adjustment of the depth of propeller 18 in the operating position so that the height of the propeller with respect tothe water body floor indicated generally at C can be controlled.

A water and material transport tube 29,;a clasification hopper 3t and a bucket hoist 31 are disposed within well 16. Hopper 30 is disposed adjacent. the stern end of well 16 and is formed of a for-aminous material such as wire mesh with all portions of the hopper disposed above the water line of the barge generally indicated at 35. The hopper is disposed in spaced relation from walls 33 of well 16 by bracket supports 32 mounted on the walls 33 and disposed to support the corner portions 34 of hopper 30. By this means there are spaces provided between the side walls of hopper 30 and walls 33 of well 16. This facilitates classification of water through the bottom and the sides of hopper 3t). Hopper 30 thus functions as a classifier in which water and smaller silica are removed from the larger shellmaterial discharged into the hopper. Thetforward end of hopper 3!) is formed with an opening to receive the discharge from end 36 of transport tube 29. The elevation of the discharge end of the'transport tube is controlled by a crank mechanism 37. By this means the elevation of discharge end 36 isadjustably controlled.

Crank mechanism 37. comprises a pair of cranks 39 mounted on a pair of shafts 40 and a connecting rod'42 connected to the bottom of discharge end 36 so that the elevation of the discharge end is controlled by controlling the degree of rotation of shafts 40.

Discharge end 36 is pivotally mounted on rod 42 and the intake end 41 of discharge tube 29 is controlled in elevation by pulley mechanism 44 mounted on davit 27. The relative lengths of transport tube 29 and well 16are formed to allow the entire transport tube to be lifted in the well above the water line. The transport tube may bestored within .well 16 above the water line for; maintenance and cleaning and also to position thetransport tube, so that no portionthereofiis below the bottom of the vbarge providing the advantage of full utilization of the barges minimum draft by elimination ofany depending. element onthe bottom of. the barge.

Transport tube 29 may be lowered to the operative position via pulley mechanism-44 whereat intake end 41 is disposed slightly above the water body floor. Pulley mechanism 44 is attached adjacent intake end 41 of transport tube 29 by a bifurcated connector 43 pivotally mounted on tube 29. In the operative position intake end 41 is disposed. to directly face propeller 18 so that the water flow stream created by the propeller is directed into intake end 41.

Transport tube 29, in greater detail, is formed of a frame comprising two spaced apart coplanar bottom braces, 50 having coplanar spaced parallel ribs 51. Ribs 51 and braces 50 form the bottom of transport tube 29. The top portion of the frame is formediby U-shaped ribs 55 similarly arranged in parallel spaced relation with the ends of each legof each rib.55 being joined to one of r the braces 50.

Wire mesh 58 of a predetermined mesh size is formed to cover the top and bottom of the transport tube. The meshsize of screen 58 will depend. upon the material whic h is,b e ing retrievedtrom the water. body floor. .As will hereinafter be seen there is considerable classification of water and small particles through screen 58 while the water and particles are transported through tube 29. Thus a smaller mesh will provide transportation of a greater amount of small particles then will a screen 58 formed of a larger mesh size.

Bucket hoist 31 is arranged to pick up shell material within hopper 3i} and transport the material to an elevated discharge port -60 from whence the material flows through transport tube 61 downwardly into a carrier barge 65" located alongside the dredger barge.

Carrier barge 65- is of conventional structure comprising a hull 67 with a cargo carrying area 68' having wire mesh end walls 69 through which water and small particles may be classified from the shells carried within the carrier barge. Bucket hoist 31- comprises drive sprockets 70 and idler sprockets 71 arranged to rotate chains 72 with the two stretches of the chains vertically disposed. Chains. 72 are arranged to mount a plurality of buckets 75. Each bucket is formed of wire meshalso so'that when wateris picked up by thebuckets in the upward position water is clasified from the shell materials carried by the bucket.

In operation of the dredger barge propeller. 18 is adjusted to be approximately one-half to three and one half. feet above the water body floor. Intake end,41 of transport tube 29 is adjusted to ride two to three inches from the water body fioor.. It is to be observed. that should the water body floor have an irregular contour that the pulleys 25 and. 44 can be adjusted to maintain propeller 18 and transport tube 29 in substantially the aforesaid relation during the time of operation of the barge.

The. spacing between propeller 18 andatube 29 is dependent upon numerous factors including available power, propeller size, size of barge, and conditions of dredging. -The propeller should preferably. create an extremely high water flow stream directed from the propeller astern into the mouth or input end 41 of transport tube 29. The turbulence of the water flow stream re-acts with the lighter materials on the water body floor C and causes the lightermaterials such as silt shells, silica particles and organic materials to become temporarily dispersed and suspended in the water flow stream. The stream is thereafter directed into transport tube 29 and thence through the tube into hopper 36 from discharge end 36 of the tube. It is noted that because of the wire mesh 53 forming the body of tube 29 there is some classification of water through the walls of the tube. However, thewater flow stream is formed of sufficient velocity to carry the remaining water within tube 29 and the solid materials through tube29 and out the discharge end 36 whereat they are directed into hopper 39. The height of discharge end 36 is adjustable to vary the relative angle of material transported through tube 29. By adjustment of this angle the percentage of water clasification may be, substantially controlled. Thus for example ifjthe transport tube is arranged on a more horizontal plane there will be a lesser amount of classification of water silt and silica capable of passing through screen 58 then if the tube 29 is arranged on a more upwardly directed angie.

It is also to be observed that the height of discharge end 36 should be adjustable so that the bottom of the transport tube 29 is above the material level within hopper 39 so that should the shell level rise beyond the bottom of the discharge end 36 ofthe transport tube the discharge-end may be accordingly raised.

It is noted that hopper 30 is formed of a wire mesh throughout its sides and'bottom so that there is a classification of water and silica capable of passing through the wire mesh forming hopper 30 while the shells and retained silica are contained within the hopper. The shells are thence lifted fromhopper 30 in buckets-75 0f the bucket elevator mechanism 31. Buckets '75 being formed of wire mesh material also classify water and smaller particles that might still be held within hopper 30. Thereafter the substantially dry and classified particles are drawn from the buckets 75 into transport tube 60 and thereafter deposited in carrier barge 65.

It is to be noted that a certain amount of shell material and silica classification is obtained by varying the distance of propeller 18 with respect to the water body floor C. If the propeller is at a higher elevation such as approximately three and one-half feet from the water body floor there will be a correspondingly greater increase percentage Wise in the low density materials put into suspension. However, should the propeller 18 be positioned substantially closer to water body floor C there will be a greater suspension of material of relatively high density. Thus a control or classification of the material to be recovered is to some degree affected by adjusting the relative depth of propeller 18.

As used herein the expression shell and/or silica includes particle matter which is capable of being dredged from a Water body fioor for purposes of recovery.

It is noted that no portion of the barge makes physical contact with the bay floor. It is also noted that the propeller 1% creating the'water flow stream also creates a force tending to move the barge forward. This force can be taken advantage of in the traversing action as shown in Fig. 3.

An anchor point is established as at 100 from whence a line 1 is attached to the stem end 13 of hull A. When line 181 is attached to the port side as at 102 of stern 13 of the barge the barge will skew so as to move in a counterclockwise direction and conversely when the line 101 is attached to the starboard side 103 the barge will skew so as to traverse in a clockwise direction. By this means the barge can be arranged to traverse in various arcuate paths about anchor point 100 in either clockwise or counterclockwise directions. As shown in Fig. 3 the line 161 may be payed out after each traverse so that the entire shell field can be scanned by traversing the barge at a slightly greater radius for each traverse.

The aforesaid scanning action of a shell field is only possible for the aforesaid barge because no portion of the shell retrieving mechanism of the barge is arranged to contact floor C so that there is a minimum impedance working against the traversing action of the barge.

Referring now to Figs. 6 and 7 there is provided a modification of the invention in which propeller 18 is sup ported by a ladder mechanism generally indicated at D which is arranged to adjustably control the angle of the propeller with respect to the floor of the water body.

Ladder D comprises two spaced apart forwardly converging beams 105 hinged adjacent forward wall 106 of Well as at 107. Braces 108 are provided to support the beams 105. A propeller support 110 is pivotally mounted on the forward end of beams 105 for vertical movement thereabout on an axle 111. Axle 111 isprovided with a worm geared driven mechanism indicated at 112 and actuated by a crank mechanism 114 so that the relative angular position of the propeller support 110 can be adjustably controlled.

Shaft 18 is arranged on its forward end with a universal joint 116 and a shaft 117 which transmits power from universal joint 116 to propeller 18. .Shaft 117 is supported on the end of propeller support 110 by a cross beam 119 which functions as a thrust bearing for shaft 117. It is thus apparent that the relative angle of propeller 18 may be adjustably varied upon actuation of crank 114.

It is to be observed that the propeller should face downwardly towards water body floor C at an angle sufficiently steep to disburse the shell material on the floor and at a shallow enough angle to provide a water stream which will be directed to be easily deflected upwardly through transport tube 29. By means of adjustment of crank 114 the optimum position of propeller 18 can controlled. 1 1

Referring now to Figs. 8 and 9 there is provided a modification of the mouth portion of transport tube 29. In the embodiment of Figs. 8 and 9 there is provided a flared mouth 121 shaped to funnel water and suspended shell particles comprising the water stream into the transport tube. Bottom portion 124 of the mouth of transport tube 29 in this embodiment is provided with a set of wheels 125 which are disposed to rest upon water body floor C. By this means the end of transport tube 29 is disposed a predetermined fixed distance above the water body floor during the traversing movement as illustrated in Fig. 3.

In Fig. 10 another modification of the bottom portion of the transport tube is provided in which there is provided a sled 128 adapted to rest on the water body floor and performing substantially the same function as wheels 125. The sled is adapted to slide across floor C during traversing movement of the barge as indicated in Fig. 3 with a minimal frictional impedance being offered to the barges traversing movement.

Wheels 125 of Figs. 8 and 9 and sled 128 of Fig. 10 function as spacer means to space the intake end of the transport tube a fixed distance above floor C while oifering only normal impedance to traverse movement of the barge. Thus the barge may be moved in. an are about a fixed anchor point solely by its own power in the manner described above in connection with Fig. 31.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be practiced within the spirit of the invention as limited only by the scope of the appended claim.

What is claimed is:

In a dredging barge for retrieving shell materials from the floor of a body of water, the combination of a propeller mounted on the hull of the barge and positioned above the floor of the water body, means to operate said propeller, a transport tube mounted on said barge having a mouth facing the water stream created by said propeller when in operation, said transport tube disposed at an angle whereat the mouth of said transport tube is disposed in spaced relation above the floor of the body of water and below the surface of the water and the discharge end of said transport tube is disposed above the water level, and whereby the water stream is disposed to place material on said floor in suspension and force the material in suspension through said transport tube, said transport tube having walls formed of foraminous material to classify a portion of Water and smaller particles of materials in suspension from the tube during transportation therethrough, a hopper disposed adjacent the discharge end of said transport tube to retrieve shells and water material discharged through the discharge end of said tube, said hopper having walls of a foraminous material and posi-' tioned above the water line of said barge whereby water and smaller particles deposited within said hopper are classified, and a bucket hoist for transporting shell material in i said hopper to elevated positions, said bucket hoist formed with buckets formed of a foraminous material to further classify water and smaller particles from the shell material.

References Cited in the file of this patent UNITED STATES PATENTS 2,061,440 Schaefer Nov. 17, 1936 2,466,753 Dusen et a1. Apr. 12, 1949 2,508,087 Bailey May 16, 1950 2,672,700 Hanks Mar. 23, 1954 FOREIGN PATENTS 69,564 Denmark July 11, 1949 

